Machine for cutting tapered screw-threads.



F. C. MASON & J. W. SHANAHAN. MACHINE FOR CUTTING TAPERED SCREW THREADS. APPLICATION FILED OCT. 25. 1915;.

1,188,469. Patented June 27,1916.

4 SHEETS-SHEET I.

mm m fi 'Fromms CMQson i 5 M Wfihanohow w. B.

eMKovhs ma COLUMBIA PLANOGRAPH 60., WASHINGTON, n. C-

F. C. MASON & J. W. SHANAHAN. MACHINE FOR CUTTING TAPERED SCREW THREADS. APPLICATION FILED OCT. 25. 1913.

.1,1 88,469. Patented Jun 27, 1916.

4 SHEETS-SHEET 2.'

THE COLUMBIA PLANOGRAPH c0., WASHINGTON, D. C.

F. C. MASON & J.

MACHINE FOR CUTTING TA W. SHANAHAN.

PERED SCREW THREADS.

APPLICATION FILED OCT. 25. I913.

Patented J 11116 27, 1916.

4 SHEETS-SHEET 3.

IIIIIIIIIII/IIIIIIIIIIIII v! 7 B- Imam ova. 'Evcmms 0.Mo.s0n I Iohn W. Shanahan I QSVWonww F. c. MASON & 1. w. SHAN AHAN. MACHINE FOR CUTTING TAFERED SCREW THREADS.

APPLICATION FILED OCT-25, l5l3.

11m owu M M m vw fi m MW F1Q Q9 M w UNITED STATES P TE T oeraon.

FRANCIS c; M so AND JOHN w. sHANAH N, or GRAND R P DS, MIoHrGAN, .AssIeNO'Rs To BISSELL CARPET SWEEPER OO P NY,. or GRAND RAPIDs,

MI'oHIGAN, A CORPORATION OF MICHIGAN.

MACHINE FOR CUTTING TAPERED soREw-THREADs.

, Specification of Letters Patent.-

Patented June 27, 1916.

Application filed October a, 1913; Serial No. 797,258.

' and JOHN WV. SHANAHAN, citizens of the United States of America, residing. at i thesame on the line 14-14 of Fig. 13.

Grand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in Machines for Cutting Tapered Screw-Threads; and we do hereby declare the following'to be a full, clear, and exact description of the in vention, such as will enable others skilled in i the art to which it" appertains to make and use the same.

Our invention relates to improvements in machines for cutting tapered screw threads, and more particularly for cutting suchthreads On the end of wooden carpetsweeper handles and the like, and its object is to provide a semi-automatic machine having variousnew an-du'seful features hereinafter more fully described and particularly pointed out in the claims.

Our device consists essentially of an ar- "bor carrying a suitable tool for cu-ttinglthe thread, said arbor being mounted on acarriage reciprocating in line wlth the axle of the arbor, an automatic chuck for holding the work, means for revolving the chuck and work, the axis of the arbor and axis of the work being inclined to form the proper taper of'the' screw, improved means for automatically reciprocating the carriage, im-

proved means for automatically opening and closing the chuck and improved means for moving the tooltoward andaway from the work, substantially as hereinafter more fully described, reference being had to the accompanying drawings, in which Figure 1 is a plan view of a ma'chine'em' bodying our invention; Fig. 2 a front elevae tion of the same; Fig. 3 a detail in plan view, showing the" parts with 1 the tool' or cutter retracted"; Fig. 4 an end elevation of a portion ofthe device shown in Fig. 3 Fig;

5 a plan View detail, showing thGtOOl advanced' readyto begin operation; Fig. 6 an end elevation" of a portion of the device, shown in Fig. 5; Fig. 7 plane projection ofthejcircumference ofthe cam wheel; Fig; 8 an end elevation of the machine; Fig. 9 a vertical section on the line '99"of Fi' 1;

Fig. 10* an enlarged sectional detail of the automatic chuck for holding the work; Fig; 11 a vertical section on the line 11-11 of F ig; 13; Fig.12 a sectional detail at right angles to Fig-11'; Fig. 13 an enlarged elevation of the carriage, with parts broken away"; and Fig. 14 a 'transverse section of pulley 3, driven by any convenient belt.

This arbor isrnounted on a bed plate 4 pivoted near the end next the pulley, as at 5, and mounted'upon a carriage 6 slidable in w'ays7 to traverse the tool'longitudinally of the work andform the screw on the same as the work'is slowly rotated. To traverse the carriage, and to move the tool into and out" of'engage'inent with the work, a shaft 8 isprovided carrying a canrwheel 9 having a cam groove engaged by a stud 11 on the carriage to traverse the carriage longitudinally. This groove has a portiorrlO which traverses the carriage in one direction during the cutting operation of the tool and a quick return portion 10 which traverses the carriage back to starting position, and a non-traversing portion 10 parallel' withthe plane of the wheel. The wheel 9 is also provided with a cam surface 12 to engage a roller 13' projecting from the plate 4 near the tool, wherebythe plate is swung on its pivot and the tool moved into engagement' with the work and a spring 14 yieldably swings the tool toward the cam wheel and awayfrom' the work when the cam does not engage the roller. The cam surface 12' operates and extends opposite the working portion 10 of the cam groove, and thus while the tool is cutting the screw it is advanced to operating position, and while the carriage is makingthe return stroke and is at restthe tool is retracted away from the work. shown in'Figs; 5 and Ga'nd'theretracted position of the same isshown in Figs. 3 and 4. The roller'1 3 is jour'naled in a yoke on the end of a'pin15 longitudinally adjustable in the plate to determine thediameter of the screw, and is held adjusted by a-suitable' set screw 16. The shaft Sis slowly rotated by worm caring 17 driven by a counter shaft 18' havingtight and loose pulleys 19 for any convenientoperat'ing belt'..

The workingposition of the tool is To hold the work, (such as a carpet sweeper handle 20) we provide a chuck 21 journaled in a suitable bearing23 and normally closed by a yieldable spring 22; said chuck is also provided with a pinion 21 engaged by a gear 25 driven by a pinion 26 connected thereto, which latter pinionis in turn rotated by a gear 27 on the shaft 8. This train of gearing may be changeable, whereby the pitch of the screw can be varied. To automatically open the chuck against the action of the spring when the screw has been formed, we provide the chuck with a grooved collar 28 engaged by one end of a lever 29 pivoted intermediate its ends and operated by a cam 30 mounted on the shaft 8. This cam swings the arm 29 on its pivot to open the chuck and release the work, and is adjusted to so operate during the time the carriage is making the return stroke and is at rest, and the tool is in retracted position. To adjust the .work longitudinally in the chuck a fixed stop 31 is provided against which the work is placed when inserting the same in the machine. 7

To form a conical screw, the ways 7 are inclined to the axis of the shaft 8 and the cam wheel 9 is made conical so that its sur face next the carriage is parallel with the movement of the carriage and the axis of the chuck is arranged parallel withthe axis of the shaft 8. If preferred, the carriage may be made to move parallel with the shaft 8, the cam wheel made cylindrical and the axis of the chuck inclined to the axis of the shaft 8 to taper the screw.

From the foregoing description the operation of our machine will be readily understood.

During the time that the carriage is making a return stroke and is at rest, that is to say, while the stud 11 is traversing the portions 10 and 10 of the groove in the wheel 9, the chuck will be opened by the cam 30 and lever 29. The finished work is then removed by the operator and another handle placed in the chuck with its end against the stop 31. Just before the carriage starts upon the working stroke the tool is advanced toward the work by the cam 12 and the clutch is allowed to close by the cam 30 passing beyond and releasing the lever 29. At the end of the working stroke the tool is retracted from the work; the return stroke and rest of the carriage again occurs and the operation repeated, the operator removing the finished handles and placingothers in the machine in succession at each cycle of operation of the machine. The machine thus performs a cycle of operations to each revolution of the shaft 8.

What we claim is V 1. A screw cutting machine comprising a main shaft, a cam wheel on the shaft provided with a cam groove and a cam peripheral portion adjacent the groove, a reciprocal carriage, a tool adapted to form a screw thread, a plate on which the tool is mounted, the plate being pivotally mounted on said carriage, a stud on the carriage to engage in said cam groove, the latter being formed' to traverse the carriage in one direction to effect the cutting operation and to traverse the carriage in the opposite direction back to starting position and also having a non-traversing portion parallel to the plane of'the cam wheel totemporarily arrest operation of the tool, and a roller on the carriage engaging the aforesaid cam peripheral portion of the cam wheel to shift said plate on its pivot and thereby move the tool into engagement with the work.

2. A screw cutting machine comprising a main shaft, a cam wheel on the shaft provided with a cam groove and a cam peripheral portion adjacent the groove, a reciprocal carriage, a tool adapted to form a screw thread, a plate on which the tool is mounted, the plate being pivotally mounted on said carriage, a stud on the carriage to engage in said cam groove, the latter being formed to traverse the carriage in one direction to effect the cutting operation and to traverse the carriage in the opposite direction back to starting position and also having a nontraversing portion parallel to the plane of the cam wheel to temporarily arrest operation of the tool, a roller on the carriage engaging the aforesaid cam peripheral portion of. the cam wheel to shift said plate on its pivot and thereby move the tool into engagement with the work, a spring to move the tool away from the work, and a rotary chuck to hold the work.

3. A screw cuttingmachine comprising a main shaft, a cam wheel on the shaft provided with a cam groove and a cam peripheral portion adjacent the groove, a reciprocal carriage, a tool adapted to form a screw thread, a plate to which the tool is connected and which has pivotal connection at one end with the carriage, a stud on the carriage engaging in said cam groove, the latter being formed to traverse the carriage in one direction to effect the cutting operation and to 115 traverse the carriage in the opposite direc- V tion back to starting position, and also having a non-traversing portion parallel with the plane of the cam on the aforesaid shaft to temporarily arrest operation of the tool, 129 a roller on the carriage engaging the aforesaid cam peripheral portion of the cam wheel to shift said plate on its pivot and thereby move the tool into engagement with the work, a chuck for the support of the work, and a connection between the chuck and the second mentioned cam operable by the latter for automatically opening the chuck during the return movement of the carriage to starting position. 3180 4. In a screw cutting machine, a base, a main shaft jo-urnaled on the base, a cam wheel on the shaft provided with a cam groove and a cam peripheral portion adjacent the groove, a dove-tailed guide member on the base, a carriage mounted to reciprocate in said dove-tailed guide, a tool adapted to form a screw thread, a plate on which the tool is mounted, the plate being pivotally mounted on said carriage, a stud on the carriage to engage in said cam groove, the latter being formed to traverse the carriage in one direction to effect the cutting operation and to traverse the carriage in the opposite direction back to starting position and also having a non-traversing portion parallel to the plane of the Wheel to temporarily arrest operation of the tool, and a spring pressed roller on the carriage engaging the aforesaid cam peripheral portion of the cam wheel to shift said plate on its pivot and thereby move the tool into engagement with the work.

In testimony whereof we afiix our signatures in presence of two witnesses.

FRANCIS G. MASON. JOHN W. SHANAHAN. Witnesses:

PALMER A. JONES, HAROLD O. VAN ANTWERP.

Copies of this potent msy be obtained tor five cents each, by addressing the "Commissioner of Ilfatentsv Wsshington, D. 0." 

